JP3052336B2 - Inkjet head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head for selectively adhering ink droplets on a recording medium.

[Prior Art] As a conventional technique, as shown in FIG.
Multiple sets of ink cavities between 410 and thin glass plate 411
420, nozzle 421, ink supply path 422, and each ink supply path 4
Forming an ink reservoir 440 that passes through 22 and holds ink,
There is an ink jet head in which a plate of a piezoelectric body 430 having electrodes 431 formed on both sides is cut into an area of about an ink cavity, and a thin glass plate is sandwiched on each ink cavity.

[Problems to be Solved by the Invention] In the conventional inkjet head, since the ink reservoir 440 is disposed on the same side as the nozzle 421 with respect to the piezoelectric body 430, the nozzle 421, the ink cavity 420, and the ink supply path 42 are provided.
2 had to be arranged in a plane, so that the entire head became large, and there was a problem that the density of the nozzles could not be increased. In particular, it is very effective to increase the size of the ink reservoir 440 to prevent crosstalk between the nozzles. To solve this problem, an ink reservoir of a considerable size is provided.

These problems have been highlighted as the number of nozzles is increased in order to improve the performance of the printer.

Accordingly, the present invention is to solve these problems, and an object of the present invention is to provide an ink jet head having a high density, a high number of nozzles, and uniform characteristics.

[Means for Solving the Problems] An inkjet head according to the present invention includes a plurality of nozzles serving as ink ejection ports, a pressure generating member arranged corresponding to each of the plurality of nozzles, and the pressure generating member. An ink reservoir for retaining ink formed on a side not facing the nozzle; an ink supply path communicating with the plurality of nozzles; and an ink supply port for supplying ink from the ink reservoir to the ink supply path. In the ink jet head, the ink supply path is formed outside a displacement region of the pressure generating member.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural view of an ink jet head according to one embodiment of the present invention. This embodiment is roughly divided into the nozzle side member A1
And a vibrator-side member A2. Using a Si single crystal substrate 40 (see FIG. 2) having a thickness of 700 μm, the nozzle 20 and the ink supply path 21 are formed in the Si single crystal part 41, and the four ink supply paths 21 are formed at the ink supply path intersection 23. Has been integrated.
On the nozzle 20, a 35 μm thick piezoelectric body is
Ten are arranged. On the piezoelectric body 10, a common electrode 14 made of Cr, Ni, and Au having a thickness of about 0.5 μm is provided so as to cover the entire surface on the nozzle 20 side, and on a surface opposite to the nozzle 20, An elastic vibrating part 12 made of Ni having a thickness of 20 μm is provided on a nozzle 20, and a wiring part 13 is arranged following the elastic vibrating part 12. Piezoelectric body 10, elastic body vibrating part 12, common electrode on nozzle 20
14 is the pressure generating member 100. Further, an ink supply port 22 is provided on the ink supply path intersection 23. The size of the nozzle 20 is 1030 μm × 1030 μm on the piezoelectric body side and 43
μm × 43 μm. An ink reservoir 30 for holding ink 50 to be supplied to the nozzle 20 is disposed on the opposite side of the piezoelectric body 10 from the nozzle, and has an ink supply port 22 and an ink supply path 21.
Through the nozzle 20.

The manufacturing process of the inkjet head according to one embodiment of the present invention will be described with reference to FIGS.

First, the nozzle side member A1 will be described with reference to FIGS. The nozzle side member A1 is manufactured using a Si single crystal substrate 40 as shown in FIG. Both sides of Si single crystal substrate 40 (Si
The [100] plane of the single crystal is thermally oxidized to a thickness of 0.1 μm.
An SiO ₂ film 42 is formed. As a result, the Si single crystal substrate 40
It has a three-layer structure composed of the single crystal part 41 and the SiO ₂ film.

The next step will be described with reference to FIG. FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along the line nn in the figure.
As shown in FIG. 3, the SiO ₂ film 42 on one side of the Si single crystal substrate 40
0] (directions of arrows XX ′ and YY ′ in the figure).

The next step will be described with reference to FIG. FIG. 4 (a) is a top view, and FIG. 4 (b) is a cross-sectional view taken along the plane PP in the figure.
The Si single crystal substrate 40 shown in FIG. 3 is etched using a mixed solution of pyrocatechol, ethylenediamine and water. After this, Si
The O ₂ film 42 is removed. Then, the Si single crystal part 41 is anisotropically etched to form the nozzle 20, the ink supply part 21 and the ink supply port intersection 23 as shown in FIG. Ink supply section
The size of 21 is 80 μm in width, 56 μm in depth, and 80 μm in length. The nozzles 20 are formed at a pitch of 1355 μm on the left, right, up and down in the drawing.

The manufacturing process of the transducer-side member A2 will be described with reference to FIGS.

The piezoelectric body 10 shown in FIG. 5 is a piezoelectric material such as a 35 μm thick lead zirconate titanate-based composite perovskite ceramic. On both sides of the piezoelectric body 10, Cr,
The common electrode 14 made of Ni, Au, or the like is formed by plating, sputtering, or the like. On the other side, a 20μm thick Ni
Alternatively, a stainless steel elastic plate 11 is joined. A polyimide adhesive or an acrylic ultraviolet curing adhesive is used for the bonding, and the thickness of the bonding layer is set to 1 μm or less, and the electrical bonding with the piezoelectric body 10 is sufficiently ensured.

The elastic body 11 of the vibrator-side member A2 in the state of FIG. 5 is processed by photolithography as shown in FIG. Numeral 12 is an elastic vibrating part, which is 800 μm × 800 μm, and has a nozzle
In the figure, they are formed at a pitch of 1355 μm on the left, right, up and down to correspond to 20. Extending from the elastic body vibrating section 12 is a wiring section 13 connected to a drive circuit (not shown). The width of the wiring portion 13 is 80 μm.

The nozzle-side member A1 and the vibrator-side member A2 formed as described above are joined using a polyimide-based adhesive or an acrylic-based UV-curable adhesive, and are bonded to the piezoelectric body 10 on the ink supply path intersection 23. Drill holes using a laser, etc.
Form 22. The diameter of the ink supply port 22 is 250 μm. Thus, an ink jet head as shown in FIG. 1 is obtained.

As described above, in the ink jet head of the present embodiment, since the ink reservoir 30 is provided on the opposite side of the pressure generating member 100 from the nozzle 20, the ink reservoir 30 is arranged with the nozzle 20. It can be provided sufficiently large without hindrance. Further, the piezoelectric body 1 constituting the pressure generating member 100
Since 0 is used as a large sheet without processing and only the elastic body 11 having good workability is processed, workability is extremely good. Further, as the nozzle side member A1, a Si single crystal substrate 40
Because it is manufactured by anisotropic etching,
It is possible to form the nozzle 20 and the ink supply path 21 with extremely high precision and a small flow path resistance. Therefore, a large number of nozzles can be arranged at high density, and an ink jet head having stable ink flying characteristics can be provided at extremely low cost.

[Effects of the Invention] According to the present invention, a sufficiently large ink reservoir is formed without affecting the arrangement of the nozzles by forming the ink reservoir on the side of the pressure generating member that does not face the nozzle. Since the ink supply port from the ink reservoir to each nozzle is formed outside the displacement region of the pressure generating member, the ink reservoir is formed on the side of the pressure generating member that does not face the nozzle. Even with this, it is possible to easily manufacture an ink jet head in which the ink ejection characteristics do not vary depending on the positions of the ink supply port and the ink supply path.

[Brief description of the drawings]

FIG. 1 is a structural view of an ink jet head according to one embodiment of the present invention. 2 to 4 are views showing a manufacturing process and a structure of a nozzle side member of an ink jet head according to one embodiment of the present invention. 5 and 6 are views showing a manufacturing process and a structure of a vibrator-side member of the inkjet head according to one embodiment of the present invention. FIG. 7 is a diagram showing a conventional example. 10 Piezoelectric body 11 Elastic body 12 Elastic body vibrating part 20 Nozzle 21 Ink supply path 30 Ink reservoir part 40 Single crystal silicon substrate 42 SiO ₂ film 50 Ink 100 Pressure generating member 420 Cavity 430 … Piezoelectric body 440… Ink reservoir

Claims (1)

(57) [Claims] A plurality of nozzles serving as ink discharge ports, a pressure generating member arranged corresponding to each of the plurality of nozzles, and an ink formed on a side of the pressure generating member not facing the nozzle. In an ink jet head comprising: an ink reservoir to be stopped; an ink supply path communicating with the plurality of nozzles; and an ink supply port for supplying the ink supply path with the ink in the ink reservoir. An ink jet head formed outside a displacement region of a pressure generating member.